
    body{
        background-color: rgb(242, 243, 247);
    }
    ul{
        list-style: none;
    }
    html{
        font-size: 5.6vw;
    }
    .snav1,.snav2,.snav3,.snav4{
        display: flex;
        flex-wrap: wrap;
        background-color: #fff;
    }
    .snav1 li,.snav2 li,.snav3 li,.snav4 li{
        width: 25%;
        display: flex;
        flex-direction: column;/*垂直排*/
        /* flex-direction: row;水平排列 */
        justify-content: center;
        align-items: center; 
        margin-bottom: 2vw;
        }

    .first,.two,.three,.four{
      /* border: 1px solid #000; */
      display: flex;
      flex-direction:column ;
    }
    .first h3, .two h3,.three h3,.four h3{
        font-size: 5vw;
        padding: 0;
        margin: 0;
        margin-top: 4vw;
        margin-top: 4vw;
        background-color: #fff;
        
      /* border: 1px solid #000; */

    }
    .first p,.two p,.three p,.four p{
      font-size: 2.5vw;
      /* border: 1px solid #000; */
    }
    .first li img,.two li img,.three li img,.four li img{
      width: 8vw;
      margin-top: 3vw;
    }

    /* footer */

    #footer {
      border: none;
      display: flex;
      flex-wrap: wrap;
      width: 100%;
      position: fixed;
      z-index: 999;
      left: 0;
      bottom: 0;
      background-color: #fff;


    }


    #footer div {
      width: 25%;
      text-align: center;
    }

    #footer p{
      font-size: 3.5vw;
    }
    .icon {
      width: 1em;
      height: 1em;
      vertical-align: -0.15em;
      fill: currentColor;
      overflow: hidden;
      width: 20%;
      font-size: 5.0vw;

    }



